Question: If $2a + b = -1$ and $7x + 8y + 4z = 2$, what is $3b + 32z + 64y + 56x + 6a$ ?
Explanation: $= 6a + 3b + 56x + 64y + 32z$ $= (3) \cdot (2a + b) + (8) \cdot (7x + 8y + 4z)$ $= (3) \cdot (-1) + (8) \cdot (2)$ $= -3 + 16$ $= 13$